Re: BuddyPress plugins and theme not loading
Okay, several more questions?
Did you manually install BuddyPress or use WPMU’s plugin browser to install BP?
Did you restart the web server after making changes to the rewrite rules in the configuration file?
In your OP, you state that you have moved the bphome theme into /wp-content/themes/. Did you also move bpmember into /wp-content/bp-themes/?
Also, look near the bottom of this installing WPMU codex article for suggestions on Lighty rewrite rules: https://codex.wordpress.org/Installing_WPMU